Talk 1: 7 PM to 7:35 PM

Title: Cryptography - Diophantine equation


Diophantine equation is an equation where only the integer solutions matter. This has shown up in various cryptographical schemes like RSA, Diffie Hellman Key Exchange, and Elliptic Curve Cryptography. In this talk, Kel Zin will analyze some interesting CTF problems related to diophantine equation.


Kel Zin is a Year 2 NUS Computer Science student and a member of Greyhats. He likes Crypto.

Talk 2: 7:35 PM to 8 PM

Title: A practical approach to Image Forensics


As the famous adage goes, “A picture is worth a thousand words”. Images are commonly used in the internet we consume everyday, from social media to work. In this talk, we explore examining what an image is and how forensics & security could apply.


Chan Jian Hao is an Information Security student at the National University of Singapore (NUS) and a member of NUS Greyhats. He enjoys fiddling with malwares and the forensics analysis of them, while at times pwning machines for penetration testing. During his free time, he spends it mindlessly playing computer games trying to escape from elohell.

Talk 3: 8 PM to 8:15 PM

Title: Hoodwinked


Steganography is the art of misdirection. The main idea is to trick a suspecting observer into thinking that nothing is there, when everything is present in plain sight. In this talk, Nigel will cover: (1) what steganography is, (2) LSB-steganography and (3) its applications in digital watermarking.


Nigel enjoys algorithmic problems and composing music, though he is not blessed enough to be good at either. Pre-covid, he would sometimes be spotted at the pool.

Talk 4: 8:15 PM to 8:30 PM

Title: An introduction to XXE attacks


As web applications become increasingly prevalent in this day and age, the potential for attackers to exploit web-based vulnerabilities in these applications becomes increasingly greater. In this talk, Brandon will touch on on XML External Entity (XXE) Attacks, a particular form of web-based attacks that is less well-known.


Brandon is an Information Security student and a member of Greyhats. He enjoys working with web-based applications as well as learning about various web exploitation techniques.